High-End Propeller with History
Every success story starts with a future-oriented idea: SPW aimed to design a user-friendly, high-quality feathering propeller with blades which feathers easy into the sailing position. This was more than 30 years ago. Meanwhile, the VARIPROP has been developed to be one of the most modern propellers of its kind through continuous innovations by the SPW engineers.
Our motivation: What are the best sailing profiles for when the aerofoil shape does not continue under water? The VARIPROP blades automatically balance themselves into the position with the least drag. This is what creates optimal sailing characteristics for your yacht
Sailing is perfected by the VARIPROP!
On this page
Award for successful engineering performance:
In 2021 the SPW GmbH again receives the renowned DNV-GL-Certificate for feathering Propellers.
Which VARIPROP is the right for your engine:
The Variprop GP 2-, 3-, 4- and 5-blade models
For smaller sailing yachts
with an engine power of 6-40 kW / 8-50 HP
For Cruising Yachts
with an engine power of 6-100 kW / 8-140 HP
for Offshore Sailors
and precise handling
A look at our VARIPROP feathering propeller. It reduces drag under sail but still produces full power when motoring. Since it is a 4 bladed prop it produces the most thrust in the aperture we have between the skeg and the hull of our Southerly 42.
Check out the Distant Shores review of the VARIPROP 4-Blade. Youtube link
SV ORIZON - Sailing in the Mediterranean… In this episode, Andis and Silvis boat is still ashore in the dry marina "Port Navy Service" and the SPW VARIPROP Feathering Propeller is assembled.
Ships using the VARIPROP:
Variprop: Simply the finest feathering propeller in the world
This is what makes a VARIPROP feathering propeller so advantageous for yacht owners::
- 15 – 20 % higher sailing speed: The water current turns the blades into the feathering position when the engine is turned off
- No disturbing propeller turbulences: Your yacht sails significantly more stable and smoother at the rudder, so you are able to sail close-hauled.
- Optimal thrust when motoring ahead as well as astern: When shifting to reverse, the leading edge of the propeller blades is turned by 180°. Consequently, the efficiency rate is the same in both directions – without the obstructive “prop walk” (paddle wheel effect). If the paddle wheel effect is beneficial to you, the pitch in reverse can be adjusted accordingly. Individual manufacturing guaranteed!
- Improved stop performance: This will ensure substantially more control when mooring in reverse.
How the Variprop 3-blade operates:
Superb German custom work instead of mass fabrication.
Every manufacturing process starts with an ingenious 3D-CAC-Design by SPW chief developer Jörg Adamczyk. Raguse & Voss from Bremerhaven – one of the most modern foundry in Germany - develop a highly precise pattern from the 3D-design using a 5-axis controlled milling machine. Thanks to computer simulation, the casting process in the mould can be precisely determined. The result: perfect propeller blade castings!
This is followed by state-of-the-art technology by SPW GmbH using computer-controlled CNC turning and milling technology.
Before SPW assembles the propellers, the VARIPROP GP blades are measured by precise laser measuring technology and precisely machined using robot technology. Only then are our propeller components ready for the final assembly.
Our guarantee: The assembly is done according to your individual order. Every VARIPROP is specifically calculated and manufactured for each customer and is then dynamically balanced by machine.
Quality checked with MRI and DNV-GL type approval (Det Norske Veritas – Germanischer Lloyd).
VARIPROP: Absolutely vibration-free! Absolutely great!
Individual Calculation for Your Yacht
A good propeller is only as good as its calculation! Especially the propeller technology, which is often referred to as the supreme discipline in shipbuilding, requires a lot of experience! Our staff in the distribution department, as well as at boat shows worldwide, have a sound knowledge of propeller technology, which requires good training and is also complemented by their own experience as water sports enthusiasts. This affinity is important to us. Numerous data, such as the overall length of the vessel, the engine data, the yacht’s displacement need to be gathered in order to calculate the propeller individually for the vessel. Not only the diameter and pitch, but also the blade profile, number of blades and much more need to be precisely determined to achieve maximum efficiency, smooth running and effectiveness.
Patented Pitch Control
Forward and reverse pitches can be changed independently of one another in just seconds, even underwater. This allows custom fine tuning according to your boating habits. In order to optimise pitch, you do not need to disassemble your VARIPROP. This can be done while the propeller is mounted on your boat. Comprehensive instructions and necessary tools are provided with every VARIPROP.
SoftStopTM Shock Absorber
A shock absorbing multidisc brake (patented) built into the VARIPROP hub reduces unpleasant shifting noises. Consequently, the end stops of the propeller are protected from wear.
High-Strength NiBrAl Bronze
NiBrAl bronze is the best material for propeller manufacturing. It is called Ice Class in professional shipping and has excellent bearing properties. This is why our VARIPROP bearings are made out of NiBrAl bronze in the most sensitive sections, especially where parts move while shifting from ahead to reverse and vice versa during manoeuvres. Meaning: Our propellers last forever! Expensive spare parts become unnecessary.
We supply the VARIPROP feathering propeller at the factory
- ready-to-install & greased
- pitch is set by SPW
All that is left for you to do is unpack, install and enjoy sailing!
When the engine is turned off, the waterflow rotates the blades automatically into the feathered position.
Benefits: Drag is almost eliminated and speed increases 15% to 20%, depending on wind conditions. Propeller turbulence vanishes and a substantially enhanced rudder effect is achieved.
When shifting into reverse, less than one shaft rotation turns the leading edge of the blades 180 degrees.
Benefits: Efficiency (thrust) in reverse is equal to forward, 30% - 40% more than all fixed propellers. You get improved stopping power, which also decreases “Prop Walk” (paddle wheel effect). In case of varying step-down gears (i.e. Yanmar Shafts) the pitches in foward and reverse are optimal set by factory.